1. Field
The following description relates to a digital content production and graphics processing technology, and more specifically, to a technology of quickly generating natural appearance terrain images.
2. Description of the Related Art
The space expressed in movies, games, and education content is increasing. However, manually producing a large-scale terrain images required in the content is not desirable because a production period becomes longer. In addition, although a background of a content mostly requires a realistic expression possible in reality even in a virtual space, the production period becomes longer for a more realistic background if it is produced manually, which is also not desirable. Thus, a method for reducing the production period and generating a terrain image of high quality with high reality is required.
To reduce a period required for the terrain generation, a minimum manual production and an automated generation by a computer are required. The automated generation method may need to be designed to generate a natural appearance terrain image.
One method of the automated terrain image generation is a procedural terrain image generation technology. This technology is for generating a complex terrain image by repeatedly applying certain rules or methods. More specifically, a noise-based terrain image generation method, such as a Perlin or fractal method, is used. However, while such a procedural terrain image generation method has an advantage in easily generating a terrain image with a minimum rule generation, it has disadvantages in that there are difficulties in generating the terrain image in a direction a user intends to proceed and that the generated terrain image has high reality locally but is different from reality globally.
Another automated terrain image generation method is a technology using a digital elevation model (hereinafter referred to as DEM). The DEM uses image data extracted from a contour, an aerial photograph, and a satellite image, etc., and expresses an altitude of the given area. The DEM is extracted from a terrain image in the real world, which is very realistic. However, there is no DEM existing that expresses a virtual terrain image according to a user's exact needs or intentions. While, as mentioned previously, various methods of automating the terrain image generation and increasing the reality exist, the methods have nonmutual advantages and disadvantages.